The Social Democrats, a political party born out of the January-February uprising, said Friday that it would boycott the election, arguing that the vote would not be fair given the tension caused by the unrest, which it blamed on the military.
In rejecting el-Ganzouri's government, 24 protest groups, including two political parties, announced the formation of their own "national salvation" government that they say represents the protesters. The group will be headed by Nobel peace laureate Mohamed ElBaradei and four deputies.
While it is unclear how many people the statement announcing the move represents, it is an attempt by the protest movement to unify its demands and leadership.
Supporters of the military staged a rival demonstration Friday across town from Tahrir, but only several thousand people turned out. They waved identical, brand new Egyptian flags that prompted activists to post on social network sites their suspicion that the demonstration may have been staged by the military.
State television, whose coverage of the crisis shows a clear, pro-military bias, gave prominence to the supporters of the generals and hosted commentators discrediting the Tahrir protesters as irresponsible youths and violent football hooligans.
"El-Ganzouri is over and done with. We want young people to take charge of the country," said Hamdi Arban, a 50-year-old lawyer who was in Tahrir Square. "We will stay here and we won't get our rights except from here," he said.
Basma el-Husseini, who directs a cultural center and was also in Tahrir, dismissed the 78-year-old el-Ganzouri as a man with little energy to keep up with the multitude of challenges facing Egypt. "They (the generals) don't get the power of the people. All they are doing now is play for time to make people fed up."
El-Ganzouri served as prime minister between 1996 and 1999 and was deputy prime minister and planning minister before that. Tantawi himself served under el-Ganzouri for three of the 20 years he spent as Mubarak's defense minister.
Addressing a televised news conference, el-Ganzouri said the military has given him greater powers than his predecessor and that he wouldn't have accepted the job if he believed Tantawi had any intention of staying in power.
"The powers given to me exceed any similar mandates," he said. "I will take full authority so I'm able to serve my country."
But el-Ganzouri appeared uncomfortable, grasping for words and repeatedly pausing as he spoke, giving rambling answers when pressed whether he could form a government that will satisfy the public when many prominent figures have shunned joining the new administration.
The choice of el-Ganzouri deepened the anger of the protesters, already seething over the military's perceived reluctance to dismantle the legacy of Mubarak's 29-year rule.
El-Ganzouri replaces Essam Sharaf, who resigned this week after nearly nine months in office. Sharaf was criticized for being weak and beholden to the generals.
Friday's protest in Tahrir was dubbed by organizers as "The Last Chance Million-Man Protest." Swelling crowds chanted, "Leave! Leave!" and "The people want to bring down the field marshal!"
ElBaradei was mobbed by hundreds of supporters as he arrived in the square and took part in Friday prayers, leaving shortly afterward. Some factions in the protest have cited ElBaradei as a possible member of a civilian presidential council they want to replace the generals.
"He is here to support the revolutionaries," said protester Ahmed Awad, 35. "He came to see for himself the tragedy caused by the military."
Fireworks lit the sky in the evening and a large banner was strung over a side street called Mohammed Mahmoud, where most of the fighting occurred, declaring that it would be renamed "Eyes of the Revolution Street," in honor of the hundreds of protesters who suffered eye injuries as a result of tear gas used by police.
About 500 protesters camped out in front of the Cabinet office, vowing to remain to prevent el-Ganzouri's government from entering the building.
Thousands of pro-democracy protesters also rallied in other cities, including at least 10,000 in Alexandria and smaller crowds in Luxor and Assiut in southern Egypt.
The military has rejected calls to immediately step down, saying its claim to power is supported by the warm welcome given to troops who took over the streets from the discredited police early in the anti-Mubarak uprising as well as an overwhelming endorsement for constitutional amendments they proposed in a March referendum.
Tantawi has offered another referendum on whether his military council should step down immediately.
Such a vote, activists say, would be divisive and likely open the door for a deal between the military and political groups, particularly the Muslim Brotherhood. Egypt's largest and best organized group, the Brotherhood is notorious for its opportunism and thirst for power. It was empowered after the fall of Mubarak, regaining legitimacy after spending nearly 60 years as an outlawed group.
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